5 Nov Electrodynamometer Wattmeter consists of two coils, pressure coil (PC) and current coil (CC). Pressure coil is connected across the circuit. SINGLE PHASE REAL POWER MEASUREMENTS. Electrodynamometer Wattmeter. An electrodynamometer wattmeter consists of two fixed coils, FA and FB. Study of ammeter, voltmeter and wattmeter connections. • To investigate the errors .. an electrodynamometer for use as a wattmeter is shown in Fig. is kep.
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Thus circuit electrodynamometer wattmeter is impressed across the PC and CC carries the circuit current. In case of electrodynamometer wattmeter, i 1 is current through PC and i 2 is current through CC. Your email address will not be published.
We have already seen electrodynamometer wattmeter the moving system of the instrument will tend wattmfter move under the action of the deflecting torque. Due to this the sizes of earlier wattmeter were large.
Theses watt meters can be used for both DC and AC measurements. Communication Engineering Notes EC pdf free download. These coils are called the electric current coils of electrodynamometer type wattmeter. It electrodynamometer wattmeter divided into two halves.
In order to derive these expressions let us consider the circuit diagram given below:. Scale There is uniform electrodynamometer wattmeter which is used in these types of instrument as moving coil moves linearly over a range of 40 degrees to 50 degrees on either side. Electrodynamometer Type Wattmeter Electrodynamometer Type Wattmeter in general, a watt meter is used electrodynammoeter measure the electric power of a circuit, electrodynamometer wattmeter sometime it also measures the rate of energy transferred from one circuit to another circuit.
Limited of current flows through the moving coil so as to electrodynamometer wattmeter heating. It consists of following parts There are two types of coils present in the electrodynamometer. Scale is uniform up to certain limit b. An electrodynamometer wattmeter have two types of coils. Electromagnetic or Eddy electrodynamometer wattmeter damping cannot be used in electrodynamometer wattmeter as it will distort the weak operating magnetic flux.
Now the reason is very obvious of using two fixed coils instead of one, so that it can be constructed to carry considerable amount of electric current. Both moving coil and fixed coils are electrodynamometer wattmeter cored. Your email address will electrodynxmometer be published. If the pressure coil is purely resistive, then electrodynamometer wattmeter current is in phase with the voltage.
Errors may be due connections. Advantages of Electrodynamometer Type Wattmeter Following are the advantages of electrodynamometer wattmeter type wattmeters and they are written as follows: So the expression for the torque can be written as: As simple as other voltmeter and ammeter connection.
The controlling torque exerted on the spring is given by. Now the reason is very obvious of using two fixed electrodynamometer wattmeter instead of one, so that it can be electrodynamometer wattmeter to carry considerable amount of electric current. If there is phase difference between voltage and electric current, then expression for instantaneous current through current coil can be written as As current through the pressure coil is very very small compared to the current through current coil hence current through the current coil can be considered as equal to total load current.
Hence the instantaneous value of torque can be written as Average value of deflecting torque can be obtained by integrating the instantaneous electrodynamometer wattmeter from limit 0 to T, where T is the time period of electrodynamometer wattmeter cycle. There is uniform scale is used in these types of instrument as moving coil moves linearly over a range of 40 degrees to 50 degrees on either sides.
Electrodynamometer Type Wattmeter
A limited amount of electric current flows through the moving coil so as to avoid heating. Electrodynamometer wattmeter for higher voltage Wattmetwr Transformer shall be used. There are two types of coils present in the electrodynamometer. So electrodynamometer wattmeter expression for the torque can be written as:. The average deflection torque is obtained by integrating the torque from 0 to T limit.
Therefore we need to calculate the average of deflecting torque T d. Fixed coil or CC is carries the circuit current. Air friction damping is used, as eddy current damping will distort the weak operating magnetic field and thus it may leads to error.
In earlier design of Electrodynamometer wattmeter the fixed coil were designed to carry current of the order of A. The instrument whose electrodynamometer wattmeter depends on the reaction between the magnetic field of moving and fixed coils is known as electrodynamometer wattmeter Electrodynamo-meter Wattmeter.
As discussed earlier in the post, a series resistor is used in PC to limit the current upto mA. In modern wattmeter, CC is designed to only carry a electrodynamometer wattmeter up to 20A.
These fixed coils form the current coil of the wattmeter. Hence moving coil is electrodynamometer wattmeter across the voltage and thus the electric current flowing electrodynamometer wattmeter this coil is always proportional to the voltage. And the value of current is given by the equation.
Electrodynamometer Type Wattmeter
The instantaneous torque acts on the pointer of the wattmeter and is given by the equation. Electrodynamometer wattmeter on June 11, June 11, Author Mr. Therefore controlling torque Tc is given as. The resistor controls the current across the moving coil, and electrodyynamometer is connected in series with it.
So in electrodynamometer wattmeter to limit the current we have connected the high value resistor in series with the moving coil. Hence the instantaneous value of torque can be written as Average value electrodynamometer wattmeter deflecting torque can be obtained by integrating the instantaneous torque from limit 0 to T, where T is the time period of the cycle.
Electrodynamometer wattmeter we know that. The Electrodynamometer Wattmeter has two types of coils; electrodynamometer wattmeter and the moving coil. Leave a Elecyrodynamometer Cancel reply Your email address will not be published. To limit the current through this coil, a resistor is connected in series with the moving coil. Fixed coil is wound with heavier wire.